Gustave, it's unlikely you will find that linkage at a FLAPS. It is considered part of the Carb itself. You can either look for another carb like it at the salvage yard, or like Brad pointed out, give Jon a call.
This is one of those issues that reminds me of someone spending all kinds of extra money trying to SAVE money. The Rochester B is the economy carb for these engines. The Carter is the Cadillac. You can get 2 Rochesters for the cost of one complete Carter. You now have an incomplete Carter. You are learning, so its normal and all, but maybe try a post in the Stovebolts Parts Wanted Forum. The guys here will look through everything they have to help you.
